Modern highways need be made and maintained under very strict standards. In particular, the surface must conform to skid friction requirements as set up for example under ASTM E274 procedures with an ASTM E501 skid test tire.
However, highways meeting acceptable standards become worn reducing the skid friction. There have been no known acceptable prior art techniques adaptable to restoring of these worn surfaces.
One problem, for example, in restoring skid friction surfaces with concrete surfaces is the potential erosion from freeze-thaw conditions if the surface seal is substantially disturbed or chipped during a roughening process.
Another problem is the inconvenience, time and cost of restoring surfaces on an existing highway where traffic need be detoured or the highway incapacitated during heavy traffic conditions.
A further problem is the large variety of concrete and asphalt surface conditions that need be resurfaced, where different roadway surfaces may need custom attention because of different concrete or aggregate conditions.
Still a further problem is meeting the required highway specifications after roughening treatment for restoring greater skid friction, which may vary from one jurisdiction to another.
Typical prior art attempts have not solved the foregoing problems. Thus, related U.S. patents are referenced as follows:
J. W. Shoemaker et al., U.S. Pat. No. 2,967,466--Jan. 10, 1961, forces dissolvable pellets into an asphalt surface to make skid pockets.
F. E. Johnston et al., U.S. Pat. No. 1,745,100--Jan. 28, 1930, uses a set of staggered machine driven hammers which impact a concrete surface with pointed ends to chip the surface away.
G. E. Perkins, U.S. Pat. No. 3,844,670--Oct. 29, 1974, and 3,905,714--Sept. 16, 1975, use a set of sharp pointed teeth on a rotary drum surface to chip the concrete highway surface away, sweeps away the residue and deposits a new concrete layer on the chipped portion.
It is a general object of this invention to improve the status of the art in restoring skid friction surfacing to worn pavement surfaces.
It is an object of this invention to produce improved skid friction surfaces to roadways worn smooth without significant removal of surface material.
It is another object of this invention to restore skid friction surfaces to roadways quickly, economically and with minimal interruption of traffic.
It is another object of this invention to restore skid friction surfaces to roadways constructed of various materials within a range of specifications so that the restored surfaces will meet required specifications.